A toner including a binder resin, wherein a toner extract obtained by drying an extraction liquid obtained through Soxhlet extraction of the toner with tetrahydrofuran (THF) has glass transition temperature Tg in a range of from 35 C. through 55 C., and a moisture-content change rate of the toner extract before and after leaving the toner extract to stand for 3 days in an environment of 40 C. and 70% RH is 0.5% or less, and wherein a specific-surface-area change rate of the toner before and after leaving the toner to stand for 3 days in an environment of 40 C. and 70% RH is in a range of from 15% through 50%.

According to one embodiment, there is provided an image forming apparatus including an image forming unit and a controller. The image forming unit is able to execute a first image formation processing using a first color material and a second image formation processing using a second color material. The controller performs image quality stabilizing processing for the first image formation processing using second color material.

A CPU selects which speed to execute a contact control of photosensitive drums and developing rollers of a plurality of process stations at, a normal speed or a speed higher than the normal speed. The CPU selects which speed to execute a separation control of the photosensitive drums and the developing rollers of the plurality of process stations at, a normal speed or a speed higher than the normal speed. The CPU further selects contact controls and separation controls so that a difference between the number of times of execution of the contact control at the speed higher than the normal speed and the number of times of execution of the separation control at the speed higher than the normal speed becomes less than or equal to a predetermined number of times.

An image forming apparatus performs a transfer residual toner collection operation including a toner adhesion step of allowing transfer residual toner to temporarily adhere to the collecting roller during execution of image forming operation, a toner moving step of moving the transfer residual toner adhered on the collecting roller to an image carrier after the image forming operation is finished, and a toner collecting step of moving the transfer residual toner from the image carrier to an intermediate transfer body so that a cleaning mechanism can collect the transfer residual toner. The control unit controls an image forming unit having developing current less than a threshold value, to apply the collecting roller with a voltage having the same polarity as toner charge polarity in the toner adhesion step, and to apply the collecting roller with a voltage having opposite polarity to the toner charge polarity in the toner moving step.

An image forming apparatus performs a transfer residual toner collection operation including a toner adhesion step of allowing transfer residual toner to temporarily adhere to the collecting roller during execution of image forming operation, a toner moving step of moving the transfer residual toner adhered on the collecting roller to an image carrier after the image forming operation is finished, and a toner collecting step of moving the transfer residual toner from the image carrier to an intermediate transfer body and collecting the transfer residual toner. The control unit controls an image forming unit having white background toner amount that is a threshold value or more, to apply the collecting roller with a voltage having the same polarity as toner charge polarity in the toner adhesion step, and to apply the collecting roller with a voltage having opposite polarity to the toner charge polarity in the toner moving step.

An electrophotographic image forming apparatus includes a latent image bearer to rotate and bear a latent image, a charging device to charge the a latent image bearer, a developing device to develop the latent image with developer including toner and use a developing voltage including an AC component, and a lubricant applicator to apply lubricant onto a surface of the latent image bearer. An amount of the lubricant applied by the lubricant applicator onto the latent image bearer per centimeter in an axial direction of the latent image bearer is equal to or greater than 0.845 mg for a running distance of 1.0 kilometer of the latent image bearer, and a difference between a largest value and a smallest value of the developing voltage is in a range of 200 V to 400 V.

An image forming apparatus according to an embodiment includes an image forming unit, a heating unit, a fan, a guide, and a control unit. The image forming unit forms an image on a recording medium. The heating unit is disposed on a downstream side of the image forming unit in a transport direction of the recording medium. The heating unit is driven with at least two temperatures, a first temperature and a second temperature lower than the first temperature. The fan generates wind. The guide guides the wind generated from the fan to the heating unit. The control unit controls the fan and the guide when the control unit controls the heating unit by switching between driving the heating unit at the first temperature and at the second temperature.

The image-forming apparatus includes multiple developing units that form images using multiple color developers, an image carrier that, in color displacement detection, carries the developers transferred thereon at mutually different image-carrying positions, an optical sensor that projects a light to the image carrier and receives a reflected light from the image carrier, and an acquirer that acquires, in response to output from the optical sensor, passage times at which the developers on the image carrier respectively pass a detection position. The optical sensor receives a diffusively reflected light from a non-transferred area of the image carrier on which the developers are not transferred. The acquirer acquires the passage times of all the developers, in response to changes in the output from the optical sensor at an output level higher than that corresponding to a diffusively reflected light from the developers on the image carrier.

An object of the present invention is to provide an image processing apparatus capable of reducing color material consumption to the maximum while maintaining the hue of an image before and after color conversion to reduce the color material consumption. The present invention is an image processing apparatus having a first lookup table to convert pixel values in a color space into pixel values of color materials, the apparatus including: an acceptable color difference derivation unit configured to derive an acceptable color difference indicating a size of a range of acceptable color difference, which corresponds to each grid point in the color space; a pixel value determination unit configured to determine pixel values of color materials, which corresponds to each of the grid points, based on the derived acceptable color difference; and a lookup table creation unit configured to create a second lookup table to convert pixel values in the color space into the determined pixel values of color materials.

An image forming apparatus includes a first image forming section capable of forming a brilliant developer image, a second image forming section including at least one image forming section capable of forming a black developer image, a transfer section capable of transferring the brilliant developer image and the black developer image onto a medium, and a controller that controls operation of the first image forming section and the second image forming section according to received print data. When forming a brilliant image based on the print data, the controller performs control to form the brilliant image in which relative position between the brilliant developer image and the black developer image is changed depending on a medium type.